Window cleaners have enough supplies to clean 21 windows per office building on a certain number of buildings. They can also clean the windows of a school with 42 windows. Altogether, there are enough supplies to clean 126 windows. How many office buildings can be washed? Identify the equation that would be used to solve this problem algebraically.
a. 21x - 42=126
b. 42x + 21=126
c. 42x - 21=126
d. 21x + 42=126

Noe has a bucket of beads. He uses them to make 8 identical necklaces and then buys 25 beads at the store. He ends up with a total of 500 beads. How many did he start with? Identify the operations needed to solve this problem.
subtraction and division
addition and multiplication
addition and division
subtraction and multiplication

Sara wanted concert tickets that were selling for $36 each, and then she got a $19 discount. She paid a total of $53 for the tickets. How many tickets did she buy? Identify the operations needed to solve this problem.
subtraction and division
subtraction and multiplication
addition and division
addition and multiplication


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